limit amount of emitted messages by build check

Author: AR-May

src/Build/BuildCheck/Infrastructure/BuildCheckManagerProvider.cs

@@ -573,7 +573,10 @@ public CheckWrapper Initialize(Check ba, ConfigurationContext configContext)
                     throw new BuildCheckConfigurationException(
                         $"The Check '{ba.FriendlyName}' failed to initialize: {e.Message}", e);
                 }
-                return new CheckWrapper(ba);
+
+                CheckWrapper wrapper = new(ba);
+                wrapper.Initialize();
+                return wrapper;
             }
 
             public CheckWrapper? MaterializedCheck { get; set; }

src/Build/BuildCheck/Infrastructure/BuildEventsProcessor.cs

@@ -242,10 +242,6 @@ private static void ReportResult(
             return;
         }
 
-        BuildEventArgs eventArgs = result.ToEventArgs(config.Severity);
-
-        eventArgs.BuildEventContext = checkContext.BuildEventContext;
-
-        checkContext.DispatchBuildEvent(eventArgs);
+        checkWrapper.ReportResult(result, checkContext, config);
     }
 }

src/Build/BuildCheck/Infrastructure/CheckWrapper.cs

@@ -7,6 +7,7 @@
 using System.Linq;
 using Microsoft.Build.BackEnd.Logging;
 using Microsoft.Build.Experimental.BuildCheck;
+using Microsoft.Build.Framework;
 
 namespace Microsoft.Build.Experimental.BuildCheck.Infrastructure;
 
@@ -17,6 +18,16 @@ internal sealed class CheckWrapper
 {
     private readonly Stopwatch _stopwatch = new Stopwatch();
 
+    /// <summary>
+    /// Maximum amount of messages that could be sent per check rule.
+    /// </summary>
+    public const int MaxMessageCountPerRule = 10;
+
+    /// <summary>
+    /// Keeps track of number of reports sent per rule.
+    /// </summary>
+    private Dictionary<string, int>? _reportsCountPerRule;
+
     public CheckWrapper(Check check)
     {
         Check = check;
@@ -29,6 +40,11 @@ public CheckWrapper(Check check)
     // In such case - configuration will be same for all projects. So we do not need to store it per project in a collection.
     internal CheckConfigurationEffective? CommonConfig { get; private set; }
 
+    internal void Initialize()
+    {
+        _reportsCountPerRule = new Dictionary<string, int>();
+    }
+
     // start new project
     internal void StartNewProject(
         string fullProjectPath,
@@ -52,6 +68,33 @@ internal void StartNewProject(
         }
     }
 
+    public void ReportResult(BuildCheckResult result, ICheckContext checkContext, CheckConfigurationEffective config)
+    {
+        if (_reportsCountPerRule is not null)
+        {
+            if (!_reportsCountPerRule.ContainsKey(result.CheckRule.Id))
+            {
+                _reportsCountPerRule[result.CheckRule.Id] = 0;
+            }
+            _reportsCountPerRule[result.CheckRule.Id]++;
+
+            if (_reportsCountPerRule[result.CheckRule.Id] == MaxMessageCountPerRule + 1)
+            {
+                checkContext.DispatchAsCommentFromText(MessageImportance.Normal, $"The check '{Check.FriendlyName}' has exceeded the maximum number of results allowed for the rule '{result.CheckRule.Id}'. Any additional results will not be displayed.");
+                return;
+            }
+
+            if (_reportsCountPerRule[result.CheckRule.Id] > MaxMessageCountPerRule + 1)
+            {
+                return;
+            }
+        }
+
+        BuildEventArgs eventArgs = result.ToEventArgs(config.Severity);
+        eventArgs.BuildEventContext = checkContext.BuildEventContext;
+        checkContext.DispatchBuildEvent(eventArgs);
+    }
+
     // to be used on eval node (BuildCheckDataSource.check)
     internal void Uninitialize()
     {

src/BuildCheck.UnitTests/EndToEndTests.cs

@@ -62,6 +62,30 @@ public void PropertiesUsageAnalyzerTest(bool buildInOutOfProcessNode)
         Regex.Matches(output, "BC0203 .* Property").Count.ShouldBe(2);
     }
 
+
+    [Theory]
+    [InlineData(true)]
+    [InlineData(false)]
+    public void WarningsCountExceedsLimitTest(bool buildInOutOfProcessNode)
+    {
+        PrepareSampleProjectsAndConfig(
+            buildInOutOfProcessNode,
+            out TransientTestFile projectFile,
+            "PropsCheckTestWithLimit.csproj");
+
+        string output = RunnerUtilities.ExecBootstrapedMSBuild($"{projectFile.Path} -check", out bool success);
+        _env.Output.WriteLine(output);
+        _env.Output.WriteLine("=========================");
+        success.ShouldBeTrue(output);
+
+        output.ShouldMatch(@"has exceeded the maximum number of results allowed for the rule");
+
+        // each finding should be found just once - but reported twice, due to summary
+        Regex.Matches(output, "BC0202: .* Property").Count.ShouldBe(2);
+        Regex.Matches(output, "BC0203: .* Property").Count.ShouldBe(20);
+    }
+
+
     [Theory]
     [InlineData(true, true)]
     [InlineData(false, true)]

src/BuildCheck.UnitTests/TestAssets/SampleCheckIntegrationTest/PropsCheckTestWithLimit.csproj

@@ -0,0 +1,22 @@
+<Project DefaultTargets="PrintEnvVar">
+    <PropertyGroup>
+        <MyProp01>$(MyProp01)</MyProp01>
+        <MyProp02>$(MyProp02)</MyProp02>
+        <MyProp03>$(MyProp03)</MyProp03>
+        <MyProp04>$(MyProp04)</MyProp04>
+        <MyProp05>$(MyProp05)</MyProp05>
+        <MyProp06>$(MyProp06)</MyProp06>
+        <MyProp07>$(MyProp07)</MyProp07>
+        <MyProp08>$(MyProp08)</MyProp08>
+        <MyProp09>$(MyProp09)</MyProp09>
+        <MyProp10>$(MyProp10)</MyProp10>
+        <MyProp11>$(MyProp11)</MyProp11>
+    </PropertyGroup>
+
+    <Target Name="PrintEnvVar">
+        <Message Text="MyPropT2 has value $(MyPropT2)" Importance="High" />
+        <PropertyGroup>
+            <MyPropT2>SomeValue</MyPropT2>
+        </PropertyGroup>
+    </Target>
+</Project>

src/MSBuild/XMake.cs

@@ -2721,6 +2721,13 @@ private static bool ProcessCommandLineSwitches(
 
                     isBuildCheckEnabled = IsBuildCheckEnabled(commandLineSwitches);
 
+                    // BuildCheck is not compatible with node reusing, see #10317.
+                    // Disable node reuse when build check is on.
+                    if (isBuildCheckEnabled)
+                    {
+                        enableNodeReuse = false;
+                    }
+
                     inputResultsCaches = ProcessInputResultsCaches(commandLineSwitches);
 
                     outputResultsCache = ProcessOutputResultsCache(commandLineSwitches);